We present the development of a numerical simulator for digital in-line holography applications. In-line holograms of arbitrarily shaped and arbitrarily located objects are calculated using generalized Huygens-Fresnel integrals. The objects are 2D opaque or phase objects. https://www.lightemupsequences.com/flash-pick-Tiki-Luau-Shaped-Thank-You-Cards-Tropical-Hawaiian-Summer-Party-Thank-You-Note-Cards-with-Envelopes-Set-of-12-top-super